NFC technology is commonly available and used for contactless exchange of information between portable devices, for example personal digital assistants like smartphones, and NFC tags including one or more information. According to the NFC standard, information is presented as NDEF (“NFC Data Exchange Format”) codes. Transmission of information between NFC device and tag normally occurs when they are brought at a relative distance of 4 cm or less.
It is also possible that a plurality of NFC tags are arranged in structures like panels, walls, or totems, in order to make a greater number of information available to a user of the portable device.
Normally all the information available in one or more NFC tags are transferred to the NFC device when the latter is put within 4 cm from the tag or tags containing the information. This can result in an excessive consumption of the device resources, e.g. of memory, thus limiting the number of possible information which can be embedded in the NFC tag.
Methods for choosing between multiple available information have been already developed and described.
WO 2012/159673 shows that different information, for example user's manual instructions, is presented to a user of a mobile device when reading a single NFC tag, depending on which application is active at the moment of reading.
US 2013/0153650 discloses that different information could be presented to a user when reading a single RFID tag depending on context, e.g. time of day, location etc.
US 2013/0181050 presents a method where a predetermined gesture, e.g. shake or tilt, is used to select which type of tag is going to be read.
Methods are also known for making the exchanged information dependent from the orientation of the portable device.
For example, EP 2493160 discloses a method wherein a mobile phone uses its accelerometer to determine its absolute orientation while reading an NFC tag to determine data transfer direction between the mobile phone and the NFC tag. Depending on the orientation communication is established or not. No selection of the information is provided by the method.
U.S. Pat. No. 8,579,196, instead, shows that the relative orientation between a scanned NFC tag and a mobile phone is used to interpret the scanned information. The mobile phone interprets the same tag as a plurality of tags, depending on an angle between the tag and an axis of the mobile phone. However, according to U.S. Pat. No. 8,579,196, the entire information included in the tag is transferred to the mobile phone, only its interpretation depending from the relative orientation. In other words, the method, rather than providing for a selection among a plurality of information, provides for a concise system of having in a single tag a plurality of information which should otherwise presented in a plurality of tags, each differing from the others for a respective angle of rotation with respect to a common reference.